The present invention relates, in general, to vessel harvesting and, in particular, to a new and useful endoscopic method for harvesting a vessel and the novel instrumentation that is utilized in carrying out the method in support of a surgical procedure such as a coronary bypass procedure or other type of vessel harvest procedure.
Generally, minimally invasive or endoscopic vessel removal and harvesting is known in the surgical field. SU 1371689 teaches a vessel removal procedure which utilizes an endoscope having a lumen therethrough. In this procedure, the small saphenous vein is grasped and held with a grasper which is introduced through the lumen of the endoscope. After connective tissue has been dissected from around the vein, the vein is then ligated and transected and removed from the lower limb of the patient through the lumen of the endoscope.
Essentially the same technique for removal of a vessel is disclosed in U.S. Pat. No. 5,373,840 which pertains to a method for harvesting a vessel such as the saphenous vein. This procedure also utilizes an endoscope having a lumen therethrough which permits the saphenous vein to be grasped by a grasping instrument and dissected. As the vein is withdrawn into the lumen of the endoscope, the endoscope is maneuvered along the length of the vein while side branches of the vein are ligated and transected whenever encountered.
Although this method provides for a minimally invasive technique, there are several drawbacks associated with this procedure. First, in practicing this method there is limited visibility of the saphenous vein and its side branches because viewing is limited to the immediate area directly in front of the endoscope. Secondly, the illumination within the subcutaneous space created by this type of endoscope is also limited to the light emitted directly at the distal portion of the endoscope. Another drawback to this type of procedure is that the side branches of the saphenous vein limit the maneuverability of the endoscope since the outer edge of the endoscope body is prevented from advancing along the trunk of the saphenous vein until the encountered side branches are ligated and transected thereby. Once freed, the endoscope is then maneuvered until the next side branch is encountered. Moreover, it has been found that methods which utilize this type of endoscope, i.e. an endoscope having a lumen, provide a working space which is very restricted because the side walls of the scope body confine the working instrumentation to a limited area.
Furthermore, the vessel harvesting method described above is typically a three-handed approach which actually requires more than one individual. In this method, one hand is required to hold and maintain the endoscope in position, while a second hand is required to hold the free end of the transected vessel with a grasper and a third hand is required to dissect connective tissue away from the vessel.
Another method for harvesting the saphenous vein is disclosed in "Vein Harvest", Alan B. Lumsden and Felmont F. Eaves, III, in Endoscopic Plastic Surgery (Quality Medical Publishing, Inc., 1995), pp. 535-543. This method provides for performing a preliminary dissection of the saphenous vein while using an open technique prior to inserting an endoscopic retractor such as those commonly used in plastic surgery. A typical endoscopic retractor is the Emory Endoplastic Retractor sold by Snowden-Pencer. In this procedure, once the subcutaneous tissue is retracted with the endoretractor, a pair of disposable 5 mm Metzenbaum laproscopic scissors are used to dissect the superior surface of the saphenous vein in order to expose the vein. The speed of the dissection of the saphenous vein in this procedure is limited by the spreading motion of the scissor blades as well as the care which must be exercised by the surgeon when dissecting the vein in this manner.
Presently, there is no known surgical method for harvesting a vessel such as the saphenous vein which addresses the major drawbacks associated with the known methods described above. These drawbacks include excessive time required in removing a section of vessel, limited movement of procedure enabling instrumentation and limited visibility and illumination in the subcutaneous region.